Fig. 3.
OGF is the specific opioid peptide involved in the growth inhibition of human HCC cells. A: effects of various endogenous and exogenous opioids on SK-HEP-1 cell number. Cells were seeded at 50,000/well into 24-well plates and treated daily with 10−6 M concentrations of a variety of opioids for 48 h. B: SK-HEP-1 cells were treated with a polyclonal antibody specific for OGF (Co172) or with preimmune serum (IgG). Compounds were replaced daily. Cell number was measured at 48 h. Data represent means ± SE for at least 2 aliquots/well from at least 2 wells/group. ***Significantly different from sterile water-treated cells (Co) at P < 0.001.